.nested-fields.plant-density-abacus-item
  = link_to_remove_nested_association(:item, f)
  = f.input :seeding_density_value, wrapper: :append do
    = f.input_field :seeding_density_value
    %span.add-on.seeding-density-unit= f.object.plant_density_abacus.human_seeding_density_unit_name

  = f.input :plants_count, wrapper: :append, required: true do
    = f.input_field :plants_count
    %span.add-on= "/"
    %span.add-on.sampling-length-unit= f.object.plant_density_abacus.human_sampling_length_unit_name
